The overall objective of this proposal is to provide a firm foundation for understanding in molecular terms (a) the developmental regulation of UDP-glucose pyrophosphorylase and (b) the coordinate regulation of tubulin gene expression in Dictyostelium discoideum. Because of the importance of gene expression in development, the proposed experiments should provide insight into the developmental process. In addtion, the work has long-term applicability to the numerous diseases affecting development. Dictyostelium discoideum is an excellent model system for studying this question. In addition, UDP-glucose pyrophosphorylase and tubulin are extremely interesting developmental proteins. Genes coding for these proteins will be studied from both biochemical and genetic orientations. The genes will be isolated and studied in great detail to identify levels of regulation, levels of gene activity during development and potential regulatory structures. Mutants with altered patterns of expression will be isolated and studied. Through genetic studies, attempts will be made to determine the number of genetic elements involved in the expression of a developmentally regulated gene, the times of their expression, their chromosomal localization with respect to the regulated gene, how the genes interact with one another and when commitment is made to specific gene expression. In the long term, mutant genes can be isolated and studied. In addition, the two approaches should merge as the genetic analysis provides clues to reasonable directions with the more biochemical studies.